The use of liquid manure and liquid fertilizers for the fertilizing of fields has increased during the past 8 or 10 years, and is expected to increase further as animal waste handling systems are developed which separate the fibrous material that has almost no value as a fertilizer from the liquids which contain relatively high concentrations of soil building chemicals. Liquid manure may be applied in either of two ways. The first way is by spraying it over the surface of the ground; and the second way is by pumping it through injector nozzles which are positioned behind soil erupting chisel points or discs or blades of a cultivator or a power driven rotary cultivator.
One problem in the latter type of application has been the arrangement for moving a large supply tank of liquid manure around a field with the injector apparatus. The problem is that liquid manure must be pumped out of the tank in which it is transported, and this requires either a pump that may be driven off a tractor hydraulic system or a pump that may be driven from the tractor power take-off. Both for cost and reliability, a p.t.o. drive is preferred.
The location of a farm tractor p.t.o. shaft is such that the customary direct slip tube link between a p.t.o. shaft and a pump on a tank trailer interferes with the use of a liquid manure injector apparatus which is most conveniently mounted upon the three point hitch of the tractor. The problem is clearly illustrated by the drawings of Jurdyc U.S. Pat. No. 3,544,010, which discloses a liquid manure spray apparatus that has a pump driven from the tractor p.t.o. As is there shown, the slip tube link between the pump and the p.t.o. shaft is quite high above the ground; and simultaneous use of such a p.t.o. drive and an injector apparatus mounted on the three point hitch of the tractor is impossible.
The prior art discloses a number of proposals for moving a substantial supply of anhydrous ammonia around a field in conjunction with injector apparatus mounted upon a tractor three point hitch; but such devices do not present the problem that exists in a liquid manure spreader because a tank of anhydrous ammonia is under high pressure so no pump is required to discharge it through the injector nozzles. Accordingly, such patents as Vinyard U.S. Pat. No. 3,752,092, Pechacek U.S. Pat. No. 3,526,342, Dountas et al U.S. Pat. No. 3,295,482, and Pattison U.S. Pat. No. 3,218,999, all dealing with anhydrous ammonia applicators, are of no help in solving the problem of providing a liquid manure tank with a p.t.o. driven pump while avoiding any interference with the use of injector apparatus mounted upon the tractor three point hitch.